Removing oil pump on 1999 3cyl. 25Hp Johnson

I have seen a lot of posts on VRO's but not much on the smaller motors. Can anyone give detailed intructions on this motor. Thanks in advance.

Re: Removing oil pump on 1999 3cyl. 25Hp Johnson

The triple 25s and 35s were only made for a few years and are nice running outboard. These out boards do not mix oil the same way as other OMC outboards. They have two fuel pumps at the front of the engine behind and below the air intake. The first pump pulls the fuel from the tank and the second pump sends the fuel to the OMS mixing chamber and then up to the carbs. The mixing chamber is under the oil tank. The oil mixes at a constant 50:1 it does not do variable ratio oiling. The outboard has two oil sensors one is in the tank for low oil and the other checks for oil in the mixing chamber. What is the model # of your 25? So why do you want to remove the OMS system? You should buy the service manual for your outboard as there many things that are unique to the 25 and 25 triple. You can get it at www.marineengine.com

Re: Removing oil pump on 1999 3cyl. 25Hp Johnson

If it was my mtr I'd get rid of the oiling system on that mtr and mix my fuel 50:1. Unless you want 3 scored cylinders. That oil pump would let fuel into the oil tank and you might have a 250:1 mix going into the mtr. Disconnect the wires off the top of the oil tank, remove it and the pump, do a little fuel line plumbing so the fuel pumps feed the carbs and you're good to go. Don't forget the 50:1 mix.

Re: Removing oil pump on 1999 3cyl. 25Hp Johnson

I am planning on removing my oil tank this week, do i just disconnect the sensor wires or do i need to use a jumper or tie together.
Tim

Re: Removing oil pump on 1999 3cyl. 25Hp Johnson

Just disconnect them and tape them up. When you remove the tank and mixing unit you'll have to do some re-plumbing on the fuel lines which isn't hard to do. Don't forget the 50:1 mix.

Re: Removing oil pump on 1999 3cyl. 25Hp Johnson

Got it, thanks for the info
Tim